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24,407 result(s) for "Test accuracy"
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Applying Grading of Recommendations Assessment, Development and Evaluation (GRADE) to diagnostic tests was challenging but doable
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group developed an approach to assess the quality of evidence of diagnostic tests. Its use in Cochrane diagnostic test accuracy reviews is new. We applied this approach to three Cochrane reviews with the aim of better understanding the application of the GRADE criteria to such reviews. We selected reviews to achieve clinical and methodological diversities. At least three assessors independently assessed each review according to the GRADE criteria of risk of bias, indirectness, imprecision, inconsistency, and publication bias. Two teleconferences were held to share experiences. For the interpretation of the GRADE criteria, it made a difference whether assessors looked at the evidence from a patient-important outcome perspective or from a test accuracy standpoint. GRADE criteria such as inconsistency, imprecision, and publication bias were challenging to apply as was the assessment of comparative test accuracy reviews. The perspective from which evidence is graded can influence judgments about quality. Guidance on application of GRADE to comparative test reviews and on the GRADE criteria of inconsistency, imprecision, and publication bias will facilitate the operationalization of GRADE for diagnostics.
GRADE guidelines: 21 part 2. Test accuracy: inconsistency, imprecision, publication bias, and other domains for rating the certainty of evidence and presenting it in evidence profiles and summary of findings tables
This article provides updated GRADE guidance about how authors of systematic reviews and health technology assessments and guideline developers can rate the certainty of evidence (also known as quality of the evidence or confidence in the estimates) of a body of evidence addressing test accuracy (TA) on the domains imprecision, inconsistency, publication bias, and other domains. It also provides guidance for how to present synthesized information in evidence profiles and summary of findings tables. We present guidance for rating certainty in TA in clinical and public health and review the presentation of results of a body of evidence regarding tests. Supplemented by practical examples, we describe how raters of the evidence can apply the GRADE domains inconsistency, imprecision, and publication bias to a body of evidence of TA studies. Using GRADE in Cochrane and other reviews as well as World Health Organization and other guidelines helped refining the GRADE approach for rating the certainty of a body of evidence from TA studies. Although several of the GRADE domains (e.g., imprecision and magnitude of the association) require further methodological research to help operationalize them, judgments need to be made on the basis of what is known so far.
GRADE guidelines: 21 part 1. Study design, risk of bias, and indirectness in rating the certainty across a body of evidence for test accuracy
This article provides updated GRADE guidance about how authors of systematic reviews and health technology assessments and guideline developers can assess the results and the certainty of evidence (also known as quality of the evidence or confidence in the estimates) of a body of evidence addressing test accuracy (TA). We present an overview of the GRADE approach and guidance for rating certainty in TA in clinical and public health and review the presentation of results of a body of evidence regarding tests. Part 1 of the two parts in this 21st guidance article about how to apply GRADE focuses on understanding study design issues in test accuracy, provide an overview of the domains, and describe risk of bias and indirectness specifically. Supplemented by practical examples, we describe how raters of the evidence using GRADE can evaluate study designs focusing on tests and how they apply the GRADE domains risk of bias and indirectness to a body of evidence of TA studies. Rating the certainty of a body of evidence using GRADE in Cochrane and other reviews and World Health Organization and other guidelines dealing with in TA studies helped refining our approach. The resulting guidance will help applying GRADE successfully for questions and recommendations focusing on tests.
Development of an interactive web-based tool to conduct and interrogate meta-analysis of diagnostic test accuracy studies: MetaDTA
Background Recommended statistical methods for meta-analysis of diagnostic test accuracy studies require relatively complex bivariate statistical models which can be a barrier for non-statisticians. A further barrier exists in the software options available for fitting such models. Software accessible to non-statisticians, such as RevMan, does not support the fitting of bivariate models thus users must seek statistical support to use R, Stata or SAS. Recent advances in web technologies make analysis tool creation much simpler than previously. As well as accessibility, online tools can allow tailored interactivity not found in other packages allowing multiple perspectives of data to be displayed and information to be tailored to the user’s preference from a simple interface. We set out to: (i) Develop a freely available web-based “point and click” interactive tool which allows users to input their DTA study data and conduct meta-analyses for DTA reviews, including sensitivity analyses. (ii) Illustrate the features and benefits of the interactive application using an existing DTA meta-analysis for detecting dementia. Methods To create our online freely available interactive application we used the existing R packages lme4 and Shiny to analyse the data and create an interactive user interface respectively. Results MetaDTA, an interactive online application was created for conducting meta-analysis of DTA studies. The user interface was designed to be easy to navigate having different tabs for different functions. Features include the ability for users to enter their own data, customise plots, incorporate quality assessment results and quickly conduct sensitivity analyses. All plots produced can be exported as either .png or .pdf files to be included in report documents. All tables can be exported as .csv files. Conclusions MetaDTA, is a freely available interactive online application which meta-analyses DTA studies, plots the summary ROC curve, incorporates quality assessment results and allows for sensitivity analyses to be conducted in a timely manner. Due to the rich feature-set and user-friendliness of the software it should appeal to a wide audience including those without specialist statistical knowledge. We encourage others to create similar applications for specialist analysis methods to encourage broader uptake which in-turn could improve research quality.
Delirium detection in older acute medical inpatients: a multicentre prospective comparative diagnostic test accuracy study of the 4AT and the confusion assessment method
Background Delirium affects > 15% of hospitalised patients but is grossly underdetected, contributing to poor care. The 4 ‘A’s Test (4AT, www.the4AT.com ) is a short delirium assessment tool designed for routine use without special training. The primary objective was to assess the accuracy of the 4AT for delirium detection. The secondary objective was to compare the 4AT with another commonly used delirium assessment tool, the Confusion Assessment Method (CAM). Methods This was a prospective diagnostic test accuracy study set in emergency departments or acute medical wards involving acute medical patients aged ≥ 70. All those without acutely life-threatening illness or coma were eligible. Patients underwent (1) reference standard delirium assessment based on DSM-IV criteria and (2) were randomised to either the index test (4AT, scores 0–12; prespecified score of > 3 considered positive) or the comparator (CAM; scored positive or negative), in a random order, using computer-generated pseudo-random numbers, stratified by study site, with block allocation. Reference standard and 4AT or CAM assessments were performed by pairs of independent raters blinded to the results of the other assessment. Results Eight hundred forty-three individuals were randomised: 21 withdrew, 3 lost contact, 32 indeterminate diagnosis, 2 missing outcome, and 785 were included in the analysis. Mean age was 81.4 (SD 6.4) years. 12.1% (95/785) had delirium by reference standard assessment, 14.3% (56/392) by 4AT, and 4.7% (18/384) by CAM. The 4AT had an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84–0.96). The 4AT had a sensitivity of 76% (95% CI 61–87%) and a specificity of 94% (95% CI 92–97%). The CAM had a sensitivity of 40% (95% CI 26–57%) and a specificity of 100% (95% CI 98–100%). Conclusions The 4AT is a short, pragmatic tool which can help improving detection rates of delirium in routine clinical care. Trial registration International standard randomised controlled trial number (ISRCTN) 53388093 . Date applied 30/05/2014; date assigned 02/06/2014.
Eating Disorder Screening: a Systematic Review and Meta-analysis of Diagnostic Test Characteristics of the SCOFF
BackgroundEating disorders affect upwards of 30 million people worldwide and often go undertreated and underdiagnosed. The purpose of this systematic review and meta-analysis was to evaluate the diagnostic accuracy of the Sick, Control, One, Fat and Food (SCOFF) questionnaire for DSM-5 eating disorders in the general population.MethodThe Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) were followed. A PubMed search was conducted among peer-reviewed articles. Information regarding validation of the SCOFF was required for inclusion. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.ResultsThe final analysis included 25 studies. The validity of the SCOFF was high across samples with a pooled sensitivity of 0.86 (95% CI, 0.78–0.91) and specificity of 0.83 (95% CI, 0.77–0.88). Subgroup analyses were conducted to examine the impact of methodology, study quality, and clinical characteristics on diagnostic accuracy. Studies with the highest sensitivity tended to be case-control studies of young women with anorexia nervosa (AN) and bulimia nervosa (BN). Studies which included more men, included those diagnosed with binge eating disorder, and recruited from large community samples tended to have lower sensitivity. Few studies reported on BMI and race/ethnicity; thus, subgroups for these factors could not be examined. No studies used reference standards which assessed all DSM-5 eating disorders.ConclusionThis meta-analysis of 25 validation studies demonstrates that the SCOFF is a simple and useful screening tool for young women at risk for AN and BN. However, there is not enough evidence to support utilizing the SCOFF for screening for the range of DSM-5 eating disorders in primary care and community-based settings. Further examination of the validity of the SCOFF or development of a new screening tool, or multiple tools, to screen for the range of DSM-5 eating disorders heterogenous populations is warranted.Trial RegistrationThis study is registered online with PROSPERO (CRD42018089906).
Systematic Review and Meta-Analysis of Studies Evaluating Diagnostic Test Accuracy: A Practical Review for Clinical Researchers-Part II. Statistical Methods of Meta-Analysis
Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies.
Piloting QUADAS-3: a revised tool for the quality assessment of diagnostic accuracy studies
QUADAS-2 is the most widely used tool for evaluating risk of bias and applicability concerns in diagnostic test accuracy studies within systematic reviews. QUADAS-2 has recently been updated to a new version, named QUADAS-3. This paper outlines the piloting process undertaken as part of the development of QUADAS-3. Multistage piloting: (1) piloting by the QUADAS-3 steering group on a set of five journal papers, (2) piloting workshop at the Global Evidence Summit attended by 16 participants, (3) think aloud interviews with seven researchers who piloted the tool while verbalizing their thoughts, and (4) piloting in five ongoing or completed systematic reviews by seven review authors who provided feedback in an online survey. Feedback on the tool was generally positive across the four piloting stages. Participants appreciated the structure of the tool, assessment at the estimate level, and the introduction of a framework to define the ideal test accuracy trial. Participants provided suggestions for improvement to the structure and wording of the tool; this led to key changes including the insertion of descriptive prompts within the QUADAS-3 domains, a section at the beginning of the tool to outline the tool's phases and when they should be completed, and clearer wording throughout the tool. Participants also identified areas where further guidance is required for users, including development of worked examples, which will be covered in the associated QUADAS-3 guidance document. Extensive piloting has ensured that feedback from potential users has been integrated into the development of QUADAS-3. What is the problem? Doctors often use tests to find out if a person has a certain condition. It is important that these tests can correctly tell people who have the condition from those who do not. This is called test accuracy. Diagnostic reviews are a type of research that bring together results from different studies about the accuracy of a test. In diagnostic reviews, researchers need to check whether the studies they include are reliable. They also need to check whether the studies match the question the review looks at. Researchers can use a tool called QUADAS-2 to do this. QUADAS-2 was made in 2011 and is now out of date. We have made a new version called QUADAS-3. In this paper, we explain how we tested the QUADAS-3 tool before making the final version. What did we do? We tested the tool in four steps. 1. The people making the tool used it on five research papers. 2. It was tested by 16 people at a conference. 3. Seven researchers said their thoughts out loud while using the tool and we gathered their feedback. 4. Seven researchers used the tool in real reviews. They gave feedback in an online survey. We updated the tool after each step. What did we find? Most people liked the QUADAS-3 tool. They also told us ways to make it better. We made changes in response to people's comments. This led to the final version of QUADAS-3. •We present methodology and findings of a multistage piloting process for QUADAS-3.•This paper has informed the update of QUADAS-2 into QUADAS-3.•Feedback from piloting of QUADAS-3 was largely positive.•Participants appreciated the tool’s new structure and estimate-level assessment.
Metadta: a Stata command for meta-analysis and meta-regression of diagnostic test accuracy data – a tutorial
Background Although statistical procedures for pooling of several epidemiological metrics are generally available in statistical packages, those for meta-analysis of diagnostic test accuracy studies including options for multivariate regression are lacking. Fitting regression models and the processing of the estimates often entails lengthy and tedious calculations. Therefore, packaging appropriate statistical procedures in a robust and user-friendly program is of great interest to the scientific community. Methods metadta is a statistical program for pooling of diagnostic accuracy test data in Stata. It implements both the bivariate random-effects and the fixed-effects model, allows for meta-regression, and presents the results in tables, a forest plot and/or summary receiver operating characteristic (SROC) plot. For a model without covariates, it quantifies the unexplained heterogeneity due to between-study variation using an I 2 statistic that accounts for the mean-variance relationship and the correlation between sensitivity and specificity. To demonstrate metadta, we applied the program on two published meta-analyses on: 1) the sensitivity and specificity of cytology and other markers including telomerase for primary diagnosis of bladder cancer, and 2) the accuracy of human papillomavirus (HPV) testing on self-collected versus clinician-collected samples to detect cervical precancer. Results Without requiring a continuity correction, the pooled sensitivity and specificity generated by metadta of telomerase for the diagnosis of primary bladder cancer was 0.77 [95% CI, 0.70, 0.82] and 0.91 [95% CI, 0.75, 0.97] respectively. Metadta also allowed to assess the relative accuracy of HPV testing on self- versus clinician-taken specimens using data from comparative studies conducted in different clinical settings. The analysis showed that HPV testing with target-amplification assays on self-samples was as sensitive as on clinician-samples in detecting cervical pre-cancer irrespective of the clinical setting. Conclusion The metadta program implements state of art statistical procedures in an attempt to close the gap between methodological statisticians and systematic reviewers. We expect the program to popularize the use of appropriate statistical methods for diagnostic meta-analysis further.
Systematic Review and Meta-Analysis of Studies Evaluating Diagnostic Test Accuracy: A Practical Review for Clinical Researchers-Part I. General Guidance and Tips
In the field of diagnostic test accuracy (DTA), the use of systematic review and meta-analyses is steadily increasing. By means of objective evaluation of all available primary studies, these two processes generate an evidence-based systematic summary regarding a specific research topic. The methodology for systematic review and meta-analysis in DTA studies differs from that in therapeutic/interventional studies, and its content is still evolving. Here we review the overall process from a practical standpoint, which may serve as a reference for those who implement these methods.